This invention relates to an improved safeguard sentry, and more particularly to radio receiving apparatus adapted for attachment to a conventional radio or television receiving set to facilitate emergency communications.
The improved safeguard sentry of the present invention is for the purpose of obtaining immediate communication with the populace of the United States. The invention is therefore useful in warning of tornadoes, hurricanes, or other capriciousness of elements of nature; in warning of threat of or actual attack by foreign enemies; to advise of threats from public enemies; in deterrence of crime; and especially in the practicing of Civil Defense exercises.
In practice, the safegurad sentry would be placed on all newly manufactured radio and television set as a normal process during their manufacture. Apparatus incorporating the same operating principles will be available for installation on existing radio and television receivers.
The improved safeguard sentry is an electronic device consisting entirely of transistorized and compact circuitry. It is a transistorized radio receiver responsive to a predetermined emergency frequency, and will receive only this signal as broadcast or transmitted. When the emergency signal is received it is an electronic tone, beep, squeal, voice, or other signal that is received and amplified, and emitted from the speaker of the radio or television set to which it is applied, said signal having at least a predetermined volume.
In one embodiment the safeguard sentry is "power on" at all times when the radio or television is switched to the "off" position, thus requiring no conscious act to place it in operation. When the power switch of the radio or television is turned to "off" position, the safeguard sentry is alert and at work, thus assuring an available audience 24 hours a day. When the power switch of the radio or television is turned to "on" position, this cuts off the power to the safeguard sentry.
As an example, the proper authority may broadcast the emergency signal above-described, and the safeguard sentry immediately begins to emit the signal, which may be a "squeal". The owner of the radio or television set then turns the set "on" to receive the broadcast instructions from the authority, and through this act simultaneously turns off the squeal or signal. If no one is in "ear shot" of the signal it simply continues until the emergency signal ceases, and stops, neither disturbing nor advising anyone, and damaging or harming nothing.
The service which may be rendered by the safeguard sentry of the invention should be appreciated and in demand in the event of any form of enemy attack, such as the approach or imminence of assault by plane or missile, to serve in keeping an evenly informed public, to rally forces, and above all to help forestall panic, one of the most grave threats to be faced by "at home America".
In another embodiment the safeguard sentry includes a switch having two operating modes. In one mode the switch connnects the safeguard sentry to a speaker, which may comprise an internal speaker. In the other operating mode, the swtich of the safeguard sentry connects operating power to the receiving set. In this mode the switch also connects the output of the safeguard sentry to the speaker of the receiving set and enables a visual signaling apparatus. The visual signaling apparatus is actuated in response to the receipt of an emergency signal by the safeguard sentry, and functions to ward both deaf persons and persons in a high background noise environment. Regardless of the operating mode, the safeguard sentry includes a volume control which prevents the audible output of the apparatus from being reduced below a predetermined level.
In still another embodiment the safeguard sentry includes circuitry responsive to the receipt of an emergency signal by the safeguard sentry to mute the speaker of receiving set. This embodiment may further include apparatus for generating an internal tone signal and/or visual output in response to receipt of the emergency signal by the safeguard sentry. Regardless of whether the emergency signal is reproduced or an internal tone signal is generated, the audible portion of the warning signal provided by the third embodiment of the invention has at least a predetermined volume.